Staff at the Automobile Association (AA) have voted for their first national strike in more than a century, in a row over proposed changes to their pension schemes.

The breakdown service's union, the Independent Democratic Union (IDU), said that 57 per cent of its 2,400 members had voted in favour of the walkout, with an 87 per cent turnout. Staff are angry at the AA's plans to cap employee pensions.

"We will look at the result and decide what we're going to do next," said the IDU national secretary Alistair Maclean. "We would rather talk with the AA and try to reach an agreement. If we don't manage to sit down with the company, we have no alternative than to follow the result of the ballot and set dates for strike action."

The AA management wants to put a cap on pensionable salaries, to raise employee contributions and to reduce the maximum annual rise in pensions paid to 2.5 per cent a year. Mr Maclean accused the AA's owners of trying to rob pensions in a move he said would cost employees. The AA expressed disappointment at the outcome of yesterday's ballot, describing the IDU as "out of touch with the real world". The breakdown service accused the IDU of "jumping the gun" by balloting AA patrols on strike action before the consultation period ends on 23 April.

"Ballots calling for industrial action are premature as we believe that most staff accept the need for change," said Andrew Strong, chief executive of AA Services. "We have committed to increase our contributions by 40 per cent, and have improved our offer by raising the cap so feel that the union is out of touch with the real world on this issue.

"We think the majority of staff will support our proposals. We want to offer all our staff a good deal on pensions. The AA is bucking the trend by proposing to keep our final salary section and career average sections open when most companies are closing theirs."

The AA said a majority of patrols did not vote in favour of strike action – which would be the first in organisation's 105 year history – as more than 400 were not part of the union. "There's still support among our patrols so we're hoping it won't go to a strike," said Sue Beeson, head of PR at the AA.

The AA's 15 million members across the country have been reassured by the self-proclaimed "fourth emergency service" that contingency plans would be enacted to ensure they received a good service, as hundreds of patrols would not be involved in any strike action.

However, the Association of British Drivers expressed concern. "It's a very sad day if people are going to be breaking down and not getting the help they need," said a spokesman. "A lot of people do rely on the AA and RAC for breakdown cover. If that's not forthcoming, that's not a good situation for drivers."

Meanwhile, members of the Rail, Maritime and Transport (RMT) union held an executive meeting yesterday to plan for a fresh ballot, after strike action timetabled for this week was ruled unlawful by the High Court. "Our dispute with Network Rail remains alive," said the RMT leader Bob Crow. "The fight to defend 1,500 safety-critical jobs out on the tracks, and safe working conditions for both our signals and maintenance staff, will not be kicked aside by one highly political court ruling."